Method for the acid treatment of clay



Feb. 21, 1939- L. R. CAMERON ET AL 2,147,733

METHOD FOR THE ACID TREATMENT OF CLAY Filed May 13, 1936 W43 W14 TEE DIS CHHEG E I Patented Feb. 21, 1939 UNITED STATES PATENT OFFICE METHOD FOR THE ACID TREATMENT OF CLAY Louis R. Cambron and woodson 0. Tucker, Jr.,

' Ocala, Fla.

Application May 13, 1936, Serial No. 79,578

2 Claims. (01. 252-2) .This invention relates to the activation of clay or argillaceous material, such for instance as bentonite, montmorillonite and the like.

Acid treatment of clays tO render'them active or to increase their activity has been practised for many years back, and although innumerable methods have been advanced in recent years dealing with relative proportions of materials, application of heat, etc., and minor changes in steps of procedure, the practice is and always has been basically the same. One angle, however, which has apparently been dealt with lightly by the proponents of the art is simplification of the apparatus and elimination or reduction of moving parts and corrosion-resistant equipment, and since the clay and acid mixture causes rapid wear and corrosion of agitators, force feed mechanism and like parts coming in contact therewith, the problem is one which merits special consideration.

I The primary object of the present invention,

therefore, is to provide an improved method of activating clay and apparatus for carrying out the method which is materially simplified with respect to prior known methods and apparatus.

'Another object is to provide a method and apparatus for activating clay whereby treatment of the clay containing any acid is accomplished without the use of moving parts or mechanism which would be damaged by contact with the acid clay mixture.

A further and more specific object is to provide an apparatusforthe acid treatment of clay or clay-like material wherein the requirement for corrosion resistant equipment in the washing process is substantially eliminated. The foregoing and other objects and advantages will become apparent in view of the following description taken in conjunction with the drawing, wherein,

Figure 1 is a diagrammatic view of an apparatus suitable for carrying out the improved method, and

Figure 2 is an enlarged detail view showing a preferred type of valve mechanism for the tanks.

5 While the illustration in the drawing is more or less diagrammatic, it is of sufl'icient detail to teach one skilled in the clay-treating art how to construct an operative installation.

Referring in detail to the drawing, I is a tank for the raw clay, this tank having therein an agitator 2 for agitating the clay to form a slime. 3 is the water line for feeding water to the agitating tank I and also to the remaining tanks to be described. A slime pump 4 is disposed adja- 55 cent the tank I, and a pipeline 5 leads from the 'is drawn off into line tank I to the pump 4 and then upwardly to a treating tank 6, which is arranged at a predetermined elevation. This tank 6 has a heating coil 6a and an agitator 'I therein. An acid line 8 extends to a suitable source of supply at its 5 inlet end and at its outlet end feeds into the tank 6.

Starting with the tank 6 and arranged in stepped relation downwardly are a series of washing tanks 9a, 9b, 9c, 9d, 9e and Bi, and extending 10 adjacent these tanks are water feed lines Ila, IIb, No, lld, He and II). II] is a waste wash water line and I2 is a short trough leading from the treating tank 6 to the first washing tank.

The last of the stepped tanks is indicated at 15 I3 and in this tank the wet clay is held previous to drying. An agitator I4 is operatively mounted in this tank. I5 is a pipe line leading from tank I3 to the receiving pan of a drier I6. This drier 'is preferably of the rotary steam drum typewell known in the art, and mounted within operative adjacency to the drum is a scraper 2I for removing the dry clay from the surface of the drum. I1

is an elevator and I8 is a conveyor for conducting the dried material to the elevator, which de- 25 livers it to a storage bin I9.

Each of the washing tanks 9a to 9] is provided with a valve 22 which is in the form of a plug mounted on a lever 23 fulcrumed at 24, the lever 23 at its upper end being controlled by a hand 30 screw 25. Also drain plugs 26 are provided in each of the-said washing tanks for drawing ofi supernatant water, and baflles 21 are provided on conduit II] to prevent overrunning of the water when the plugs 26 are drawn. 35

1 The method is preferably carried out as follows:

Raw or neutral clay is introduced into the tank I and water is added from the pipe line 3, the clay being thoroughly agitated in this tank to form a slurry or slime. This slurry or slime is pumped into tank 6 by pump 4 and is agitated in this tank while acid is added in the desired quantity through line 8. If the clay has previously been dried and ground it may be introduced directly into the acid solution in tank 6. After the desired acid solution and clay mixture has been formed in tank 6, the mixture-is'heated by steam coil 6a and agitated for the desired length of time. After proper treatment, the mixture is then allowed to flow through the trough I2 into the tank 911, where more water is added to bring the mixture up to the desired volume. The clay is now allowed to settle, and'after substantially complete settling the supernatant wash water III. The valve plug 22 is from line Ila directed into the tank 90, and the clay is agitated and a slurry is formed which is forced to flow through the valve opening into the next succeeding tank 8b, where the solution is again brought up to the desired volume by the addition of water, it necessary, and allowed to settle. Again ai'ter settling the supernatant water is drawn off into line ill, the valve plug of this tank removed, water applied and the clay agitated and caused to flow into the tank 90; this procedure being continued until the clay reaches the bottom tank [3.

In causing the clay to flow from tank 81 into tank l3, as small an amount of water as eiflciently possible is used and no additional water is added in tank It.

In the tank I! the clay is continually agitated to keep it in fluid form, and from this tank the clay is allowed to flow through the line I into the receiving pan of drier IS. The pipe line II is preferably provided with a valve Isa in order to regulate the flow so that the drier IE will be able to take care of the clay delivered thereto. The scraper 2i removes the dry clay from the surface of the drier and the clay thus removed falls into the conveyor 20. The temperature of the drier should be regulated to dry the clay adhering to the surface of the drier drum by the time it reaches scraper 2i, and the travel of the conveyor 20 should be regulated to take care of the dried clay delivered thereto from the drum, as will be obvious.

From the conveyor 20, the clay goes up through the elevator l1 and is delivered into the storage bin 19, from which it may be sacked for shipment.

It will be noted that no acid contacts any oi the moving parts outslde'oi' the agitator I, since the acid is not added until the clay reaches tank 6, and by the time the acid-clay mixture reaches the tank It, the acid has been washed clear of the clay. Furthermore, the number 0! moving parts in the complete installation are considerably less than those embodied in the conventional apparatus used for the acid-treatment of clay.

It will be understood that certain variations in 2,147,788 now released, a stream of water under pressure the steps of the method and type of apparatus used may be made without departing from the scope of the invention as defined in the appended claims.

We claim:

1. The method'of activating clay which consists in forming a fluent slurry of clay and water, conducting the slurry to a container sufl'iciently elevated to permit subsequent washing treatment of the clay by gravity flow, adding acid to the slurry and agitating and heating the acid-clay mixture, and then washing the clay in steps by permitting the clay to settle, drawing off supernatant water and again forming a slurry by adding water to the settled clay and repeating the washing steps until the clay is substantially free of acid.

2. The method of activating clay which consists in forming a fluent slurry of raw clay and water, conducting the slurry to a container sufflciently elevated to permit subsequent washing treatment of the clay by downward flow, adding acid to the slurry and agitating and heating the acid-clay mixture, and then washing the clay in repeated steps by permitting the clay to settle, drawing oiI supernatant water and adding water under pressure to the settled clay to form a slurry and at the same time wash the clay from one washing tank to another until the clay is substantially free of acid.

i 3. The method of activating clay which consists in forming a fluent slurry of clay and water, conducting the slurry to a container sufliciently elevated to permit subsequent washing treatment of the clay by downward flow, adding acid to the slurry and agitating and heating the acid-clay mixture, adding water to bring the mixture to the desired volume, and then washing the clay in repeated steps by permitting the clay to settle, drawing oil supernatant water and adding water to the settled clay to form a slurry and conducting the slurry so formed from one washing tank to another until the clay is substantially free of acid, and then passing the clay to a drier to dry the clay.

LOUIS R. CAMERON.

WOODSON C. TUCKER, JR. 

